Eco-efficiency of disposable and reusable surgical instruments—a scissors case

Purpose

In recent years, the rising costs and infection control lead to an increasing use of disposable surgical instruments in daily hospital practices. Environmental impacts have risen as a result across the life cycle of plastic or stainless steel disposables. Compared with the conventional reusable products, different qualities and quantities of disposable scissors have to be taken into account. An eco-efficiency analysis can shed some light for the potential contribution of those products towards a sustainable development.

Methods

Disposable scissors made of either stainless steel or fibre-reinforced plastic were compared with reusable stainless steel scissors for 4,500 use cycles of surgical scissors used in Germany. A screening life cycle assessment (LCA) and a life cycle costing were performed by following ISO 14040 procedure and total cost of ownership (TCO) from a customer perspective, respectively. Subsequently, their results were used to conduct an eco-efficiency analysis.

Results and discussion

The screening LCA showed a clear ranking regarding the environmental impacts of the three types of scissors. The impacts of the disposable steel product exceeds those of the two others by 80 % (disposable plastic scissors) and 99 % (reusable steel scissors), respectively. Differences in TCO were smaller, however, revealing significant economic advantages of the reusable stainless steel product under the constraints and assumptions of this case study. Accordingly, the reusable stainless steel product was revealed as the most eco-efficient choice. It was followed by the plastic scissors which turned out to be significantly more environmentally sound than the disposable stainless steel scissors but also more cost-intensive.

Conclusions

The overall results of the study prove to be robust against variations of critical parameters for the prescribed case study. The sensitivity analyses were also conducted for LCA and TCO results. LCA results are shown to be reliable throughout all assumptions and data uncertainties. TCO results are more dependent on the choice of case study parameters whereby the price of the disposable products can severely influence the comparison of the stainless steel and the plastic scissors. The costs related to the sterilisation of the reusable product are strongly case-specific and can reduce the economic benefit of the reusable scissors to zero. Differences in environmental and economic break-even analyses underline the comparatively high share of externalised environmental costs in the case of the disposable steel product.     

Reusable vs. disposable cups revisited: guidance in life cycle comparisons addressing scenario,model, and parameter uncertainties for the US consumer

Purpose

Despite interest in an environmentally conscious decision between disposable and reusable cups, a comprehensive and current study for US consumers is not yet available. Guidance in favor of single-use cups rely on outdated or non-ISO-compliant results with limited uncertainty information. Such claims are insufficiently generalizable. This article delivers an updated comparative life cycle impact assessment of reusable ceramic cups and single-use expanded polystyrene cups.

Methods

The ReCiPe midpoint model was selected. Scenario uncertainties are addressed by evaluating compliant standard dishwashing appliance models from 2004 to 2013 used in 26 US subregional utility grids. A utility snapshot from 2009 is applied with extension to recent shifts in generation from increased penetration of natural gas and renewable energy. Parameter uncertainty is quantified through statistical methods.

Results

Where there is statistical difference, results almost entirely favor reusable cups in the USA. For climate change, 16 % of users have higher impact for ceramic cups washed in 2013 by minimally compliant dishwashers. Higher climate change impacts for 32 % of reusable cup users is indicated with 2004 average dishwashers, though using a cup twice between washes shifts the impact in favor of the reusable cup.

Conclusions

Disposable cup scenarios do not account for film sleeves, lids, printing, and less conservative shipping weights and distances and therefore reflect a best case scenario. Impact for reusable cups is expected to decrease further as the electricity mix becomes less CO₂-intensive with replacement of coal-fired generators by natural gas, wind, and solar and as less efficient dishwashers are replaced with new units compliant to current laws.     

Environmental trade-offs across cascading lithium-ion battery life cycles

Purpose

The purpose of this study was to analyze the environmental trade-offs of cascading reuse of electric vehicle (EV) lithium-ion batteries (LIBs) in stationary energy storage at automotive end-of-life.

Methods

Two systems were jointly analyzed to address the consideration of stakeholder groups corresponding to both first (EV) and second life (stationary energy storage) battery applications. The environmental feasibility criterion was defined by an equivalent-functionality lead-acid (PbA) battery. A critical methodological challenge addressed was the allocation of environmental impacts associated with producing LIBs across the EV and stationary use systems. The model also tested sensitivity to parameters such as the fraction of battery cells viable for reuse, service life of refurbished cells, and PbA battery efficiency.

Results and discussion

From the perspective of EV applications, cascading reuse of an LIB in stationary energy storage can reduce net cumulative energy demand and global warming potential by 15 % under conservative estimates and by as much as 70 % in ideal refurbishment and reuse conditions. When post-EV LIB cells were compared directly to a new PbA system for stationary energy storage, the reused cells generally had lower environmental impacts, except in scenarios where very few of the initial battery cells and modules could be reused and where reliability was low (e.g., life span of 1 year or less) in the secondary application.

Conclusions

These findings demonstrate that EV LIB reuse in stationary application has the potential for dual benefit—both from the perspective of offsetting initial manufacturing impacts by extending battery life span as well as avoiding production and use of a less-efficient PbA system. It is concluded that reuse decisions and diversion of EV LIBs toward suitable stationary applications can be based on life cycle centric studies. However, technical feasibility of these systems must still be evaluated, particularly with respect to the ability to rapidly analyze the reliability of EV LIB cells, modules, or packs for refurbishment and reuse in secondary applications.

     

An environmental impact comparison of single-use and reusable thermally controlled shipping containers

Purpose

Pharmaceutical and biological materials require thermally controlled environments when being transported between manufacturers, clinics, and hospitals. It is the purpose of this report to compare the life cycle impacts of two distinct logistical approaches to packaging commonly used in cold chain logistics and to identify the method of least environmental burden. The approaches of interest are single-use packaging utilizing containers insulated with either polyurethane or polystyrene and reusable packaging utilizing containers with vacuum-insulated panels.

Methods

This study has taken a cradle-to-grave perspective, which covers material extraction, manufacture, assembly, usage, transportation, and end-of-life realities. The functional unit of comparison is a 2-year clinical trial consisting of 30,000 individual package shipments able to maintain roughly 12 L of payload at a controlled 2–8 °C temperature range for approximately 96 h. Published life-cycle inventory data were used for process and material emissions. A population-centered averaging method was used to estimate transportation distances to and from clinical sites during container use. Environmental impacts of the study include global warming potential, eutrophication potential, acidification potential, photochemical oxidation potential, human toxicity potential, and postconsumer waste.

Results and discussion

The average single-use approach emits 1,122 tonnes of CO₂e compared with 241 tonnes with the reusable approach over the functional unit. This is roughly a 75 % difference in global warming potential between the two approaches. Similar differences exist in other impact categories with the reusable approach showing 60 % less acidification potential, 65 % less eutrophication potential, 85 % less photochemical ozone potential, 85 % less human toxicity potential, and 95 % less postconsumer waste. The cradle-to-gate emissions of the single-use container were the overwhelming cause of its high environmental burden as 30,000 units were required to satisfy the functional unit rather than 772 for the reusable approach. The reusable container was about half the mass of the average single-use container, which lowered its transportation emissions below the single-use approach despite an extra leg of travel.

Conclusions

The reusable logistical approach has shown to impose a significantly smaller environmental burden in all impact categories of interest. A sensitivity analysis has shown some leeway in the degree of the environmental advantage of the reusable approach, but it confirms the conclusion as no case proved otherwise.     

When consumer behavior dictates life cycle performance beyond the use phase: case study of inkjet cartridge end-of-life management

Purpose

Conventional wisdom suggests that product reuse can provide environmental savings. The purpose of this study is to first compare the environmental impacts of retail refilling and remanufactured inkjet cartridge alternatives to production of new inkjet cartridges, and then determine the extent to which consumer behavior can influence life cycle outcomes.

Methods

A life cycle inventory was developed for an inkjet cartridge with an integral print head using material composition data collected from cartridge disassembly and material processing, product manufacturing, and transportation inputs estimated from market data and the ecoinvent database in SimaPro 7.3. Although previous comparative life cycle assessment (LCA) studies for printer cartridges typically use “pages printed” or a variation thereof for the functional unit, “cartridge use cycles” is more suitable for examining reused inkjet cartridge alternatives that depend on the inkjet cartridge end-of-life (EOL) route chosen by the consumer. Since multiple reuse cycles achieved from refilling by a retailer was of specific interest, a functional unit defined in the form of “five use cycles” included the mode and manner in which consumers purchased inkjet cartridge use cycles.

Results and discussion

Cartridge refills present the lowest environmental impact, offering a 76 % savings in global warming potential (GWP) impact compared to production and purchase of a new inkjet cartridge alternative, followed by the remanufacturing case, which provided a 36 % savings in GWP impact compared to the new inkjet cartridge. However, results varied widely, even switching to favor new cartridge purchase, depending on how consumer transport was modeled, specifically the mode of travel, travel patterns (number of trips), and method of allocating impact to each trip.

Conclusions

Refilling an original equipment manufacturer (OEM) cartridge four consecutive times provides the best alternative for reducing environmental impact for those consumers that purchase inkjet cartridges one at a time. On the other hand, consumers that purchase multiple cartridges in a single trip to a retailer reduce environmental impact more by transport minimization than by refilling. Results reinforce the need for more comprehensive inclusion of consumer behavior when modeling life cycle environmental impact of product alternatives.     

PET bottle reverse logistics—environmental performance of California’s CRV program

Purpose

Disposable beverage bottles made of polyethylene terephthalate (PET) stand in sharp contrast to many other disposable plastic packaging systems in the US for their high level of post-consumer recovery for recycling. This is due in part to container deposit programs in several US states, such as the California Redemption Value (CRV) program. We investigate the impacts of PET bottle recycling in the CRV program to evaluate its effectiveness at reducing environmental burdens.

Methods

We develop a life cycle model using standard process LCA techniques. We use the US LCI database to describe the energy production infrastructure and the production of primary materials. We describe the inventory and logistical requirements for materials recovery on the basis of state-maintained statistics and interviews with operators and industry representatives. We report inventory indicators describing energy, freight, and waste disposal requirements. We report several impact indicators based on CML and TRACI-2.0 techniques. We apply system expansion to compare post-consumer activities to produce secondary polymer against equivalent primary production.

Results and discussion

While bottle collection is distributed across the state, processing is more centralized and occurs primarily near urban centers. The average distance traveled by a bottle from discard to recovery is 145–175 km. Recycling requires 0.45–0.66 MJ of primary energy/L of beverage, versus 3.96 MJ during the pre-consumer phase. Post-consumer environmental impacts are significantly lower than pre-consumer impacts, with the exception of eutrophication. The results are robust to model sensitivity, with allocation of fuel for bottle collection being the most significant parameter. Curbside collection is slightly more energy efficient than consumer drop-off, and is subject to smaller parametric uncertainty. Recycling has the potential for net environmental benefits in five of seven impact categories, the exceptions being smog (marginal benefits) and eutrophication (increased impacts).

Conclusions

California’s decentralized program for collecting and processing PET bottles has produced a system which generates a large stream of post-consumer material with minimal environmental impact. The selection of a reclamation locale is the most significant factor influencing post-consumer impacts. If secondary PET displaces primary material, several environmental burdens can be reduced.

Recommendations and perspectives

Our results suggest that deposit programs on disposable packaging are an effective policy mechanism to increase material recovery and reduce environmental burdens. Deposit programs for other packaging systems should be considered.     

Various Effects of Sandblasting of Dental Restorative Materials

Background

Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials.

Methods

We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC) group and non-ultrasonic cleaning (NUSC) group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength.

Results

For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group.

Conclusions

Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials.     

Analysis of raw cork production in Portugal and Catalonia using life cycle assessment

Purpose

This study aims to (1) evaluate the environmental impacts associated with the three types of raw cork produced in Portuguese cork oak woodlands (in Alentejo region) considering two alternative practices for stand establishment (plantation and natural regeneration), (2) compare the environmental impacts of raw cork production in Portuguese cork oak woodlands and in Catalonian cork oak forests, and (3) assess the influence of different allocation criteria for partitioning the environmental impacts between the different types of raw cork produced.

Methods

A cradle-to-gate approach was adopted starting with stand establishment up to cork storage in a field yard. The system boundaries include all management operations undertaken during the following stages: stand establishment, stand tending, cork stripping, and field recovery. The allocation of the environmental impacts to reproduction, second, and virgin cork was based on mass and market price criteria. An alternative allocation approach was simulated by allocating environmental impacts also to the wood produced in the cork oak stands. The impact assessment was performed using the characterization factors recommended by the International Reference Life Cycle Data System (ILCD).

Results and discussion

In Portugal, cork produced from naturally regenerated stands has a better environmental performance than cork produced from planted stands, but the differences are smaller than 10 %. Different management models of cork oak stands in Portugal and Catalonia (agro-silvopastoral system and forest system, respectively) originate different impact levels, which tend to be significantly lower in Catalonia. The environmental hot spots in the two regions are also distinct. In Catalonia, they are associated with cleaning, road maintenance, and worker and cork transport. In Portugal, they are fertilization, pruning, and cleaning. The two allocation criteria affect significantly the results obtained for virgin cork in Portugal and for virgin and second cork in Catalonia. Besides, when impacts are also allocated to wood, mass allocation should be avoided as it would not create incentives for a sustainable management of cork oak stands.

Conclusions

The environmental impact from Catalonian cork may be reduced by decreasing mechanized shrub cleaning and road maintenance operations through the introduction of livestock in cork oak forests, and also by a better planning of management operations. For the Portuguese cork, improvements may be achieved by optimizing fertilizer dosage, planting nitrogen-fixing crops and pastures that improve soil quality, avoiding unnecessary operations, improving the efficiency of management operations, and increasing tree density.     

Comparative life cycle assessment of smartphone reuse: repurposing vs. refurbishment

Purpose

Waste management for end-of-life (EoL) smartphones is a growing problem due to their high turnover rate and concentration of toxic chemicals. The versatility of modern smartphones presents an interesting alternative waste management strategy: repurposing. This paper investigates the environmental impact of smartphone repurposing as compared to traditional refurbishing using Life Cycle Assessment (LCA).

Methods

A case study of repurposing was conducted by creating a smartphone “app” that replicates the functionality of an in-car parking meter. The environmental impacts of this prototype were quantified using waste management LCA methodology. Studied systems included three waste management options: traditional refurbishment, repurposing using battery power, and repurposing using a portable solar charger. The functional unit was defined as the EoL management of a used smartphone. Consequential system expansion was employed to account for secondary functions provided; avoided impacts from displaced primary products were included. Impacts were calculated in five impact categories. Break-even displacement rates were calculated and sensitivity to standby power consumption were assessed.

Results and discussion

LCA results showed that refurbishing creates the highest environmental impacts of the three reuse routes in every impact category except ODP. High break-even displacement rates suggest that this finding is robust within a reasonable range of primary cell phone displacement. The repurposed smartphone in-car parking meter had lower impacts than the primary production parking meter. Impacts for battery-powered devices were dominated by use-phase charging electricity, whereas solar-power impacts were concentrated in manufacturing. Repurposed phones using battery power had lower impacts than those using solar power, however, standby power sensitivity analysis revealed that solar power is preferred if the battery charger is left plugged-in more than 20 % of the use period.

Conclusions

Our analysis concludes that repurposing represents an environmentally preferable EoL option to refurbishing for used smartphones. The results suggest two generalizable findings. First, primary product displacement is a major factor affecting whether any EoL strategy is environmentally beneficial. The benefit depends not only on what is displaced, but also on how much displacement occurs; in general, repurposing allows freedom to target reuse opportunities with high “displacement potential.” Second, the notion that solar power is preferable to batteries is not always correct; here, the rank-order is sensitive to assumptions about user behavior.     

Environmental payback periods of reusable alternatives to single-use plastic kitchenware products

Purpose

Many consumers are transitioning away from single-use plastic products and turning to reusable alternatives. Oftentimes, this change is being made with the assumption that these alternatives have fewer environmental impacts; however, reusable products are frequently made from more environmentally intensive materials and have use phase impacts. This study used LCA to examine the GWP, water consumption, and primary nonrenewable energy use associated with reusable alternatives for single-use plastic kitchenware products and determined environmental payback periods.

Methods

The environmental impacts for each reusable alternative are calculated on the functional units of 1 use, 1 year (5 uses/week), and 5 years (5 uses/week). Payback periods are calculated for each reusable alternative and defined as the number of times a consumer must reuse an alternative in order for the environmental impact per use to be equivalent to the environmental impact for the single-use product. The research explored the sensitivity of the results to different consumer washing and reuse behaviors, as well as local conditions such as overall transportation distances and the carbon intensity of different electricity grids. Product types studied included straws (4 reusable, 2 single-use), sandwich storage (2 reusable, 3 single-use), coffee cups (3 reusable, 2 single-use), and forks (1 single-use, 3 reusable).

Results and discussion

Environmental impacts associated with the reusable alternatives were highly dependent on the use phase due to dishwashing, making payback period sensitive to washing frequency and method, and for GWP, carbon intensity of the energy grid (used for water heating). For single-use products, the material/manufacturing phase was the largest contributor to overall impacts. It was found that nine of the twelve reusable alternatives were able to breakeven in all three environmental indicators. The coffee cup product type was the only product type to have one reusable alternative, the ceramic mug, and have the shortest payback period for all three impact categories. Both the bamboo straw and beeswax wrap were unable to breakeven in any scenario due to high use phase impacts from manual washing.

Conclusions

The research found that reusable alternatives can payback the environmental impacts of GWP, water consumption, and energy use associated with their more resource intensive materials, but it is dependent on number of uses, consumer behavior, and for GWP, carbon intensity of the energy grid. A key takeaway is that consumer behavior and use patterns influence the ultimate environmental impact of reusable kitchenware products.

Recommendations

Some recommendations for consumers looking to reduce the overall impact of kitchenware products include the following:

1. 1)

   Not always assuming reusable is the best option.

2. 2)

   Extending product lifetime.

3. 3)

   Researching which reusable option has the lowest impact.

4. 4)

   Following best practice washing behaviors.

5. 5)

   Not washing products after every use.

6. 6)

   Advocating for integration of renewables into the local energy grid.

7. 7)

   Reducing consumption of these product types (reusable or single-use).

     

A cascaded life cycle: reuse of electric vehicle lithium-ion battery packs in energy storage systems

Purpose

Lithium-ion (Li-ion) battery packs recovered from end-of-life electric vehicles (EV) present potential technological, economic and environmental opportunities for improving energy systems and material efficiency. Battery packs can be reused in stationary applications as part of a “smart grid”, for example to provide energy storage systems (ESS) for load leveling, residential or commercial power. Previous work on EV battery reuse has demonstrated technical viability and shown energy efficiency benefits in energy storage systems modeled under commercial scenarios. The current analysis performs a life cycle assessment (LCA) study on a Li-ion battery pack used in an EV and then reused in a stationary ESS.

Methods

A complex functional unit is used to combine energy delivered by the battery pack from the mobility function and the stationary ESS. Various scenarios of cascaded “EV mobility plus reuse in stationary clean electric power scenarios” are contrasted with “conventional system mobility with internal combustion engine vehicles plus natural gas peaking power.” Eight years are assumed for first use; with 10 years for reuse in the stationary application. Operational scenarios and environmental data are based on real time-of-day and time-of-year power use. Additional data from LCA databases are utilized. Ontario, Canada, is used as the geographic baseline; analysis includes sensitivity to the electricity mix and battery degradation. Seven environmental categories are assessed using ReCiPe.

Results and discussion

Results indicate that the manufacturing phase of the Li-ion battery will still dominate environmental impacts across the extended life cycle of the pack (first use in vehicle plus reuse in stationary application). For most impact categories, the cascaded use system appears significantly beneficial compared to the conventional system. By consuming clean energy sources for both use and reuse, global and local environmental stress reductions can be supported. Greenhouse gas advantages of vehicle electrification can be doubled by extending the life of the EV batteries, and enabling better use of off-peak low-cost clean electricity or intermittent renewable capacity. However, questions remain concerning implications of long-duration use of raw material resources employed before potential recycling.

Conclusions

Li-ion battery packs present opportunities for powering both mobility and stationary applications in the necessary transition to cleaner energy. Battery state-of-health is a considerable determinant in the life cycle performance of a Li-ion battery pack. The use of a complex functional unit was demonstrated in studying a component system with multiple uses in a cascaded application.

     

A life cycle assessment of residential waste management and prevention

Purpose

The oft-cited waste hierarchy is considered an important rule of thumb to identify preferential waste management options and places waste prevention at the top. Nevertheless, it has been claimed that waste prevention can sometimes be less favorable than recycling because (1) recycling decreases only the primary production of materials, whereas waste prevention may reduce a combination of both primary and low-impact secondary production, and (2) waste prevention decreases the quantity of material recycled downstream and the avoided impacts associated with recycling. In response to this claim, this study evaluates the life cycle effects of waste prevention activities (WPAs) on a residential waste management system.

Methods

This life cycle assessment (LCA) contrasts the net impacts of a large residential solid waste management system (including sanitary landfilling, anaerobic digestion, composting, and recycling) with a system that incorporates five WPAs, implemented at plausible levels (preventing a total of 3.6 % of waste generation tonnage) without diminishing product service consumption. WPAs addressed in this LCA reduce the collected tonnage of addressed advertising mail, disposable plastic shopping bags, newspapers, wine and spirit packaging, and yard waste (grass).

Results and discussion

In all cases, the WPAs reduce the net midpoint and endpoint level impacts of the residential waste management system. If WPAs are incorporated, the lower impacts from waste collection, transportation, sorting, and disposal as well as from the avoided upstream production of goods, more than compensate for the diminished net benefits associated with recycling and the displaced electricity from landfill gas utilization.

Conclusions

The results substantiate the uppermost placement of waste prevention within the waste hierarchy. Moreover, further environmental benefits from waste prevention can be realized by targeting WPAs at goods that will be landfilled and at those with low recycled content.     

Life cycle environmental impacts of carbonated soft drinks

Purpose

The UK carbonated drinks sector was worth £8 billion in 2010 and is growing at an annual rate of 4.9 %. In an attempt to provide a better understanding of the environmental impacts of this sector, this paper presents, for the first time, the full life cycle impacts of carbonated soft drinks manufactured and consumed in the UK. Two functional units are considered: 1 l of packaged drink and total annual production of carbonated drinks in the UK. The latter has been used to estimate the impacts at the sectoral level. The system boundary is from ‘cradle to grave’. Different packaging used for carbonated drinks is considered: glass bottles (0.75 l), aluminium cans (0.33 l) and polyethylene terephthalate (PET) bottles (0.5 and 2 l).

Materials and methods

The study has been carried out following the ISO 14040/44 life cycle assessment (LCA) methodology. Data have been sourced from a drink manufacturer as well as the CCaLC, Ecoinvent and Gabi databases. The LCA software tools CCaLC v2.0 and GaBi 4.3 have been used for LCA modelling. The environmental impacts have been estimated according to the CML 2001 method.

Results and discussion

Packaging is the main hotspot for most environmental impacts, contributing between 59 and 77 %. The ingredients account between 7 and 14 % mainly due to sugar; the manufacturing stage contributes 5–10 %, largely due to the energy for filling and packaging. Refrigeration of the drink at retailer increases global warming potential by up to 33 %. Transport contributes up to 7 % to the total impacts.

Conclusions

The drink packaged in 2 l PET bottles is the most sustainable option for most impacts, including the carbon footprint, while the drink in glass bottles is the worst option. However, reusing glass bottles three times would make the carbon footprint of the drink in glass bottles comparable to that in aluminium cans and 0.5 l PET bottles. If recycling of PET bottles is increased to 60 %, the glass bottle would need to be reused 20 times to make their carbon footprints comparable. The estimates at the sectoral level indicate that the carbonated drinks in the UK are responsible for over 1.5 million tonnes of CO₂ eq. emissions per year. This represented 13 % of the GHG emissions from the whole food and drink sector or 0.26 % of the UK total emissions in 2010.     

Development of a program model to evaluate the potential for reuse of single-use medical devices: results of a pilot test study

Single-use medical devices (SUDs, or disposables) have become a major expense in hospital budgets. The need for cost reduction and the availability of sterilization technologies other than the autoclave have prompted hospitals worldwide to begin reusing disposables, in many cases without proper assessment of the true costs (time, personnel, etc) and ease/difficulty of implementation of an institutional reuse program. Our group has developed a rigorous program model to evaluate SUDs for reuse. The program comprises 3 sequential protocols: (1) device audit, (2) laboratory evaluation, and (3) clinical evaluation. Use of this model can produce scientific and financial data sufficient for any institution interested in reuse to reach an initial decision about its feasibility. In addition to the testing outcomes, regulatory requirements, the position of manufacturers and third-party reprocessors, and legal and ethical concerns must be considered. A successful reuse program must include ongoing evaluations to ensure that the safety levels and cost savings established during the initial audit and evaluation phases continue. Herein, we give the rationale and details of our program model and discuss results of our pilot application of the "ideal" protocol in a real-world context.     

Life cycle assessment of light-emitting diode downlight luminaire—a case study

Purpose

Light-emitting diode (LED) technology is increasingly being used for general lighting. Thus, it is timely to study the environmental impacts of LED products. No life cycle assessments (LCA) of recessed LED downlight luminaires exist in the literature, and only a few assessments of any type of LED light source (component, lamp and luminaire) are available.

Methods

The LCA of a recessed LED downlight luminaire was conducted by using the data from the luminaire manufacturer, laboratory measurements, industry experts and literature. The assessment was conducted using SimaPro LCA software. EcoInvent and European Reference Life Cycle Database were used as the databases. The LCA included a range of environmental impacts in order to obtain a broad overview. The functional unit of the LCA was one luminaire used for 50,000 h. In addition, the sensitivity of the environmental impacts to the life was studied by assessing the LED downlight luminaire of 36,000 h and 15,000 h useful life and to the used energy sources by calculating the environmental impacts using two average energy mixes: French and European.

Results and discussion

The environmental impacts of the LED luminaire were mostly dominated by the energy consumption of the use. However, manufacturing caused approximately 23 % of the environmental impacts, on average. The environmental impacts of manufacturing were mainly due to the driver, LED array and aluminium parts. The installation, transport and end of life had nearly no effect on the total life cycle impacts, except for the end of life in hazardous waste. The life cycle environmental impacts were found to be sensitive to the life of the luminaire. The change from the French to the European average energy mix in use resulted to an even clearer dominance of the use stage.

Conclusions

The case study showed that the environmental impacts of the LED downlight luminaire were dominated by the use-stage energy consumption, especially in the case of the European energy mix in use. Luminous efficacy is, thus, a relatively appropriate environmental indicator of the luminaire. As LED technology possesses generally higher luminous efficacy compared to conventional ones, the LED luminaire is considered to represent an environmentally friendly lighting technology. However, data gaps exist in the data in LED product manufacturing and its environmental impacts. The environmental impacts of different LED products need to be analysed in order to be able to precisely compare the LED technology to the conventional lighting technologies.     

Environmental and economic optimisation of the floor on grade in residential buildings

Purpose

The goal of the study was to determine the preferred composition of the floor on grade in residential buildings in the Belgian context from a life cycle environmental and financial perspective. In addition to the life cycle costs, the required investments were evaluated to take into account budget restrictions. The analysis of current available materials and techniques allows both the designer and building owner to extend their decision criteria from mainly investment cost to life cycle aspects as well.

Methods

In this study, the potential environmental impact was assessed by considering the environmental external cost of the floors. Several existing methods were combined to enable a full assessment, taking the ExternE methodology (willingness to pay) as the main base. The ecoinvent database was used to gather the inventory data but was adapted to increase the representativeness for Belgium. The financial evaluation included both the investment and life cycle aspects. The latter was analysed through the sum of the present values of all costs occurring during the life span of the floor.

Results and discussion

The necessary assumptions (e.g. transport, end-of-life treatment, cleaning, life span, economic parameters) and the adaptations to the ecoinvent data are transparently reported. The methodological steps (e.g. monetary valuation, transmission losses, equivalent degree days, Pareto optimisation) are elaborated in detail. This allows the results, which are graphically presented, to be correctly interpreted. The contribution of the life cycle stages and the optimisation potential of the considered impacts are discussed.

Conclusions

The environmental external cost based on the willingness to pay to reduce environmental impacts proved to be relatively low, representing about 9?% of the financial cost. The cost reduction of current common practice was estimated to be about 20 and 60?% from a financial and environmental perspective, respectively. The insulation level and the floor covering were identified as the most important optimisation parameters.

Recommendations

Internalisation of environmental external costs might be an important step to achieve more sustainable solutions. However, it is recommended to consider financial and environmental external costs separately too because both contain important information for the decision maker. Because it is hard (if not impossible) to increase the insulation level of the floor on grade later on in the life cycle of the building, a high insulation value should be a priority during construction. The floor covering can more easily be adapted and is thus considered a secondary priority.     

Comparative LCA of ethanol versus gasoline in Brazil using different LCIA methods

Purpose

The main objective of this study is to expand the discussion about how, and to what extent, the environmental performance is affected by the use of different life cycle impact assessment (LCIA) illustrated by the case study of the comparison between environmental impacts of gasoline and ethanol form sugarcane in Brazil.

Methods

The following LCIA methods have been considered in the evaluation: CML 2001, Impact 2002+, EDIP 2003, Eco-indicator 99, TRACI 2, ReCiPe, and Ecological Scarcity 2006. Energy allocation was used to split the environmental burdens between ethanol and surplus electricity generated at the sugarcane mill. The phases of feedstock and (bio)fuel production, distribution, and use are included in system boundaries.

Results and discussion

At the midpoint level, comparison of different LCIA methods showed that ethanol presents lower impacts than gasoline in important categories such as global warming, fossil depletion, and ozone layer depletion. However, ethanol presents higher impacts in acidification, eutrophication, photochemical oxidation, and agricultural land use categories. Regarding to single-score indicators, ethanol presented better performance than gasoline using ReCiPe Endpoint LCIA method. Using IMPACT 2002+, Eco-indicator 99, and Ecological Scarcity 2006, higher scores are verified for ethanol, mainly due to the impacts related to particulate emissions and land use impacts.

Conclusions

Although there is a relative agreement on the results regarding equivalent environmental impact categories using different LCIA methods at midpoint level, when single-score indicators are considered, use of different LCIA methods lead to different conclusions. Single-score results also limit the interpretability at endpoint level, as a consequence of small contributions of relevant environmental impact categories weighted in a single-score indicator.     

Using life cycle thinking to analyze environmental labeling: the case of appearance wood products

Purpose

Growing public concern about the current state of our planet led to the creation of numerous regulations, standards, and certifications for the protection of humans and the environment. Ecolabels were defined for products such as cleaning products, paints, and many others. Wood building products are no exception. The objective of this study is to analyze the existing ecolabelling programs for appearance wood products in nonresidential applications and to evaluate them relatively to their effective role in environment protection or reduction of environment footprint.

Methods

The research was conducted on the most common International Organization for Standardization (ISO) type I ecolabels in North America, the European Union, and Japan. Certification schemes applicable to appearance wood products for nonresidential applications were considered. In a life cycle assessment perspective, certification criteria were compared regarding their ability to consider and integrate environment impacts.

Results and discussion

A wide range of ecolabels can apply to appearance wood products, from indoor air quality to wood from sustainable forest management. Moreover, it has been found that among all certification schemes studied, those integrating the whole life cycle were the most relevant.

Conclusions

The remaining limitation of ISO type I ecolabels is the lack of environmental information enabling the differentiation between products bearing the same ecolabel. This can be overcome by ISO type III environmental product declarations. Thus, allowing a better understanding of the implications related with the use of wood products compared to other materials in the nonresidential building sector.     

Utilization of recovered wood in cascades versus utilization of primary wood—a comparison with life cycle assessment using system expansion

Purpose

A cascading utilization of resources is encouraged especially by legislative bodies. However, only few consecutive assessments of the environmental impacts of cascading are available. This study provides answers to the following questions for using recovered wood as a secondary resource: (1) Does cascading decrease impacts on the environment compared to the use of primary wood resources? (2) What aspects of the cascading system are decisive for the life cycle assessment (LCA) results?

Methods

We conducted full LCAs for cascading utilization options of waste wood and compared the results to functionally equivalent products from primary wood, thereby focusing on the direct effects cascading has on the environmental impacts of the systems. In order to compare waste wood cascading to the use of primary wood with LCA, a functional equivalence of the systems has to be achieved. We applied a system expansion approach, considering different options for providing the additionally needed energy for the cascading system.

Results and discussion

We found that the cascading systems create fewer environmental impacts than the primary wood systems, if system expansion is based on wood energy. The most noticeable advantages were detected for the impact categories of land transformation and occupation and the demand of primary energy from renewable sources. The results of the sensitivity analyses indicate that the advantage of the cascading system is robust against the majority of considered factors. Efficiency and the method of incineration at the end of life do influence the results.

Conclusions

To maximize the benefits and minimize the associated environmental impacts, cascading proves to be a preferable option of utilizing untreated waste wood.     

A life cycle assessment case study of ground rubber production from scrap tires

Purpose

The number of scrap tires generated in China has grown dramatically every year. Generation of ground rubber from scrap tires is the dominant management option in China. It is necessary to assess the environmental impacts of ground rubber production from scrap tires to provide technical advices on a cleaner production.

Methods

Production of ground rubber from recycled scrap tires consist of three steps: rubber powder preparation, devulcanization, and refining. A process life cycle assessment (LCA) of ground rubber production from scrap tires is carried out, and Eco-indicator 99 method coupled with ecoinvent database is applied to evaluate the environmental impacts of this process.

Results and discussion

During the ground rubber production stage, the impact factor of respiratory inorganic is the most serious one. Devulcanization has the highest environmental load of about 66.2 %. Moreover, improvement on the flue gas treatment contributes to a cleaner production and a more environmental-friendly process. Applying clean energy can largely reduce environmental load by about 21.5 %.

Conclusions

The results can be a guidance to reduce environmental load when producing ground rubber from scrap tires. Meanwhile, increasing energy efficiency, improving environmental protection equipment, and applying clean energy are the effective measures to achieve this goal.